I was thinking if someone could implement Supplementary services protocols (ITU-T Q950) based on ROSE (ITU-T X.219) to work with Yate's ss7 signaling module. It's already implemented in libpri (used in asterisk) but I am not sure if we can somehow integrate its source code to fit in Yate's design. List of operations can be found in Table 1/Q.950. Personally I think implementing a few of those operations such as ECT, Diversion and AdviceOfCharge would suffice for now.